/*
- * unix_io.c --- This is the Unix I/O interface to the I/O manager.
+ * unix_io.c --- This is the Unix (well, really POSIX) implementation
+ * of the I/O manager.
*
* Implements a one-block write-through cache.
*
- * Copyright (C) 1993, 1994, 1995 Theodore Ts'o.
+ * Includes support for Windows NT support under Cygwin.
+ *
+ * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
+ * 2002 by Theodore Ts'o.
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Public
#endif
#include <fcntl.h>
#include <time.h>
+#ifdef __linux__
+#include <sys/utsname.h>
+#endif
+#ifdef HAVE_SYS_IOCTL_H
+#include <sys/ioctl.h>
+#endif
+#ifdef HAVE_SYS_MOUNT_H
+#include <sys/mount.h>
+#endif
#if HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
+#if HAVE_SYS_RESOURCE_H
#include <sys/resource.h>
+#endif
+
+#if defined(__linux__) && defined(_IO) && !defined(BLKGETSIZE)
+#define BLKROGET _IO(0x12, 94) /* Get read-only status (0 = read_write). */
+#endif
#include "ext2_fs.h"
#include "ext2fs.h"
char *buf;
unsigned long block;
int access_time;
- int dirty:1;
- int in_use:1;
+ unsigned dirty:1;
+ unsigned in_use:1;
};
#define CACHE_SIZE 8
-#define WRITE_VIA_CACHE_SIZE 4 /* Must be smaller than CACHE_SIZE */
+#define WRITE_DIRECT_SIZE 4 /* Must be smaller than CACHE_SIZE */
+#define READ_DIRECT_SIZE 4 /* Should be smaller than CACHE_SIZE */
struct unix_private_data {
int magic;
int dev;
int flags;
int access_time;
+ ext2_loff_t offset;
struct unix_cache cache[CACHE_SIZE];
+ struct struct_io_stats io_stats;
};
static errcode_t unix_open(const char *name, int flags, io_channel *channel);
static errcode_t unix_flush(io_channel channel);
static errcode_t unix_write_byte(io_channel channel, unsigned long offset,
int size, const void *data);
+static errcode_t unix_set_option(io_channel channel, const char *option,
+ const char *arg);
+static errcode_t unix_get_stats(io_channel channel, io_stats *stats)
+;
+static void reuse_cache(io_channel channel, struct unix_private_data *data,
+ struct unix_cache *cache, unsigned long long block);
+static errcode_t unix_read_blk64(io_channel channel, unsigned long long block,
+ int count, void *data);
+static errcode_t unix_write_blk64(io_channel channel, unsigned long long block,
+ int count, const void *data);
+
+/* __FreeBSD_kernel__ is defined by GNU/kFreeBSD - the FreeBSD kernel
+ * does not know buffered block devices - everything is raw. */
+#if defined(__CYGWIN__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
+#define NEED_BOUNCE_BUFFER
+#else
+#undef NEED_BOUNCE_BUFFER
+#endif
static struct struct_io_manager struct_unix_manager = {
EXT2_ET_MAGIC_IO_MANAGER,
unix_read_blk,
unix_write_blk,
unix_flush,
- unix_write_byte
+#ifdef NEED_BOUNCE_BUFFER
+ 0,
+#else
+ unix_write_byte,
+#endif
+ unix_set_option,
+ unix_get_stats,
+ unix_read_blk64,
+ unix_write_blk64,
};
io_manager unix_io_manager = &struct_unix_manager;
+static errcode_t unix_get_stats(io_channel channel, io_stats *stats)
+{
+ errcode_t retval = 0;
+
+ struct unix_private_data *data;
+
+ EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
+ data = (struct unix_private_data *) channel->private_data;
+ EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
+
+ if (stats)
+ *stats = &data->io_stats;
+
+ return retval;
+}
+
/*
* Here are the raw I/O functions
*/
+#ifndef NEED_BOUNCE_BUFFER
static errcode_t raw_read_blk(io_channel channel,
struct unix_private_data *data,
- unsigned long block,
+ unsigned long long block,
int count, void *buf)
{
errcode_t retval;
- size_t size;
+ ssize_t size;
ext2_loff_t location;
int actual = 0;
size = (count < 0) ? -count : count * channel->block_size;
- location = (ext2_loff_t) block * channel->block_size;
+ data->io_stats.bytes_read += size;
+ location = ((ext2_loff_t) block * channel->block_size) + data->offset;
if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) {
retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
goto error_out;
goto error_out;
}
return 0;
-
+
error_out:
memset((char *) buf+actual, 0, size-actual);
if (channel->read_error)
size, actual, retval);
return retval;
}
+#else /* NEED_BOUNCE_BUFFER */
+/*
+ * Windows and FreeBSD block devices only allow sector alignment IO in offset and size
+ */
+static errcode_t raw_read_blk(io_channel channel,
+ struct unix_private_data *data,
+ unsigned long block,
+ int count, void *buf)
+{
+ errcode_t retval;
+ size_t size, alignsize, fragment;
+ ext2_loff_t location;
+ int total = 0, actual;
+#define BLOCKALIGN 512
+ char sector[BLOCKALIGN];
+
+ size = (count < 0) ? -count : count * channel->block_size;
+ data->io_stats.bytes_read += size;
+ location = ((ext2_loff_t) block * channel->block_size) + data->offset;
+#ifdef DEBUG
+ printf("count=%d, size=%d, block=%lu, blk_size=%d, location=%llx\n",
+ count, size, block, channel->block_size, (long long)location);
+#endif
+ if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) {
+ retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
+ goto error_out;
+ }
+ fragment = size % BLOCKALIGN;
+ alignsize = size - fragment;
+ if (alignsize) {
+ actual = read(data->dev, buf, alignsize);
+ if (actual != alignsize)
+ goto short_read;
+ }
+ if (fragment) {
+ actual = read(data->dev, sector, BLOCKALIGN);
+ if (actual != BLOCKALIGN)
+ goto short_read;
+ memcpy(buf+alignsize, sector, fragment);
+ }
+ return 0;
+
+short_read:
+ if (actual>0)
+ total += actual;
+ retval = EXT2_ET_SHORT_READ;
+
+error_out:
+ memset((char *) buf+total, 0, size-actual);
+ if (channel->read_error)
+ retval = (channel->read_error)(channel, block, count, buf,
+ size, actual, retval);
+ return retval;
+}
+#endif
static errcode_t raw_write_blk(io_channel channel,
struct unix_private_data *data,
- unsigned long block,
+ unsigned long long block,
int count, const void *buf)
{
- size_t size;
+ ssize_t size;
ext2_loff_t location;
int actual = 0;
errcode_t retval;
else
size = count * channel->block_size;
}
+ data->io_stats.bytes_written += size;
- location = (ext2_loff_t) block * channel->block_size;
+ location = ((ext2_loff_t) block * channel->block_size) + data->offset;
if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) {
retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
goto error_out;
}
-
+
actual = write(data->dev, buf, size);
if (actual != size) {
retval = EXT2_ET_SHORT_WRITE;
goto error_out;
}
return 0;
-
+
error_out:
if (channel->write_error)
retval = (channel->write_error)(channel, block, count, buf,
errcode_t retval;
struct unix_cache *cache;
int i;
-
+
data->access_time = 0;
for (i=0, cache = data->cache; i < CACHE_SIZE; i++, cache++) {
cache->block = 0;
cache->dirty = 0;
cache->in_use = 0;
if ((retval = ext2fs_get_mem(channel->block_size,
- (void **) &cache->buf)))
+ &cache->buf)))
return retval;
}
return 0;
}
/* Free the cache buffers */
-static void free_cache(io_channel channel,
- struct unix_private_data *data)
+static void free_cache(struct unix_private_data *data)
{
struct unix_cache *cache;
int i;
-
+
data->access_time = 0;
for (i=0, cache = data->cache; i < CACHE_SIZE; i++, cache++) {
cache->block = 0;
cache->dirty = 0;
cache->in_use = 0;
if (cache->buf)
- ext2fs_free_mem((void **) &cache->buf);
+ ext2fs_free_mem(&cache->buf);
cache->buf = 0;
}
}
+#ifndef NO_IO_CACHE
/*
- * Try to find a block in the cache. If get_cache is non-zero, then
- * if the block isn't in the cache, evict the oldest block in the
- * cache and create a new cache entry for the requested block.
+ * Try to find a block in the cache. If the block is not found, and
+ * eldest is a non-zero pointer, then fill in eldest with the cache
+ * entry to that should be reused.
*/
-static struct unix_cache *find_cached_block(io_channel channel,
- struct unix_private_data *data,
- unsigned long block,
- int get_cache)
+static struct unix_cache *find_cached_block(struct unix_private_data *data,
+ unsigned long long block,
+ struct unix_cache **eldest)
{
struct unix_cache *cache, *unused_cache, *oldest_cache;
int i;
-
+
unused_cache = oldest_cache = 0;
for (i=0, cache = data->cache; i < CACHE_SIZE; i++, cache++) {
if (!cache->in_use) {
- unused_cache = cache;
+ if (!unused_cache)
+ unused_cache = cache;
continue;
}
if (cache->block == block) {
(cache->access_time < oldest_cache->access_time))
oldest_cache = cache;
}
- if (!get_cache)
- return 0;
-
- /*
- * Try to allocate cache slot.
- */
- if (unused_cache)
- cache = unused_cache;
- else {
- cache = oldest_cache;
- if (cache->dirty)
- raw_write_blk(channel, data,
- cache->block, 1, cache->buf);
- }
+ if (eldest)
+ *eldest = (unused_cache) ? unused_cache : oldest_cache;
+ return 0;
+}
+
+/*
+ * Reuse a particular cache entry for another block.
+ */
+static void reuse_cache(io_channel channel, struct unix_private_data *data,
+ struct unix_cache *cache, unsigned long long block)
+{
+ if (cache->dirty && cache->in_use)
+ raw_write_blk(channel, data, cache->block, 1, cache->buf);
+
cache->in_use = 1;
+ cache->dirty = 0;
cache->block = block;
cache->access_time = ++data->access_time;
- return cache;
}
/*
struct unix_cache *cache;
errcode_t retval, retval2;
int i;
-
+
retval2 = 0;
for (i=0, cache = data->cache; i < CACHE_SIZE; i++, cache++) {
if (!cache->in_use)
continue;
-
+
if (invalidate)
cache->in_use = 0;
-
+
if (!cache->dirty)
continue;
-
+
retval = raw_write_blk(channel, data,
cache->block, 1, cache->buf);
if (retval)
}
return retval2;
}
-
-
+#endif /* NO_IO_CACHE */
static errcode_t unix_open(const char *name, int flags, io_channel *channel)
{
errcode_t retval;
int open_flags;
struct stat st;
+#ifdef __linux__
+ struct utsname ut;
+#endif
if (name == 0)
return EXT2_ET_BAD_DEVICE_NAME;
- retval = ext2fs_get_mem(sizeof(struct struct_io_channel),
- (void **) &io);
+ retval = ext2fs_get_mem(sizeof(struct struct_io_channel), &io);
if (retval)
return retval;
memset(io, 0, sizeof(struct struct_io_channel));
io->magic = EXT2_ET_MAGIC_IO_CHANNEL;
- retval = ext2fs_get_mem(sizeof(struct unix_private_data),
- (void **) &data);
+ retval = ext2fs_get_mem(sizeof(struct unix_private_data), &data);
if (retval)
goto cleanup;
io->manager = unix_io_manager;
- retval = ext2fs_get_mem(strlen(name)+1, (void **) &io->name);
+ retval = ext2fs_get_mem(strlen(name)+1, &io->name);
if (retval)
goto cleanup;
memset(data, 0, sizeof(struct unix_private_data));
data->magic = EXT2_ET_MAGIC_UNIX_IO_CHANNEL;
+ data->io_stats.num_fields = 2;
if ((retval = alloc_cache(io, data)))
goto cleanup;
-
+
open_flags = (flags & IO_FLAG_RW) ? O_RDWR : O_RDONLY;
+ if (flags & IO_FLAG_EXCLUSIVE)
+ open_flags |= O_EXCL;
#ifdef HAVE_OPEN64
- data->dev = open64(name, open_flags);
+ data->dev = open64(io->name, open_flags);
#else
- data->dev = open(name, open_flags);
+ data->dev = open(io->name, open_flags);
#endif
if (data->dev < 0) {
retval = errno;
goto cleanup;
}
+
+#ifdef BLKROGET
+ if (flags & IO_FLAG_RW) {
+ int error;
+ int readonly = 0;
+
+ /* Is the block device actually writable? */
+ error = ioctl(data->dev, BLKROGET, &readonly);
+ if (!error && readonly) {
+ close(data->dev);
+ retval = EPERM;
+ goto cleanup;
+ }
+ }
+#endif
+
+#ifdef __linux__
+#undef RLIM_INFINITY
+#if (defined(__alpha__) || ((defined(__sparc__) || defined(__mips__)) && (SIZEOF_LONG == 4)))
+#define RLIM_INFINITY ((unsigned long)(~0UL>>1))
+#else
+#define RLIM_INFINITY (~0UL)
+#endif
/*
- * Work around a bug in 2.4.10+ kernels where writes to block
- * devices are wrongly getting hit by the filesize limit.
+ * Work around a bug in 2.4.10-2.4.18 kernels where writes to
+ * block devices are wrongly getting hit by the filesize
+ * limit. This workaround isn't perfect, since it won't work
+ * if glibc wasn't built against 2.2 header files. (Sigh.)
+ *
*/
- if ((flags & IO_FLAG_RW) &&
+ if ((flags & IO_FLAG_RW) &&
+ (uname(&ut) == 0) &&
+ ((ut.release[0] == '2') && (ut.release[1] == '.') &&
+ (ut.release[2] == '4') && (ut.release[3] == '.') &&
+ (ut.release[4] == '1') && (ut.release[5] >= '0') &&
+ (ut.release[5] < '8')) &&
(fstat(data->dev, &st) == 0) &&
(S_ISBLK(st.st_mode))) {
struct rlimit rlim;
-
- rlim.rlim_cur = rlim.rlim_max = ((unsigned long)(~0UL));
+
+ rlim.rlim_cur = rlim.rlim_max = (unsigned long) RLIM_INFINITY;
setrlimit(RLIMIT_FSIZE, &rlim);
getrlimit(RLIMIT_FSIZE, &rlim);
if (((unsigned long) rlim.rlim_cur) <
setrlimit(RLIMIT_FSIZE, &rlim);
}
}
+#endif
*channel = io;
return 0;
cleanup:
if (data) {
- free_cache(io, data);
- ext2fs_free_mem((void **) &data);
+ free_cache(data);
+ ext2fs_free_mem(&data);
}
if (io)
- ext2fs_free_mem((void **) &io);
+ ext2fs_free_mem(&io);
return retval;
}
if (--channel->refcount > 0)
return 0;
+#ifndef NO_IO_CACHE
retval = flush_cached_blocks(channel, data, 0);
+#endif
if (close(data->dev) < 0)
retval = errno;
- free_cache(channel, data);
- if (channel->private_data)
- ext2fs_free_mem((void **) &channel->private_data);
+ free_cache(data);
+
+ ext2fs_free_mem(&channel->private_data);
if (channel->name)
- ext2fs_free_mem((void **) &channel->name);
- ext2fs_free_mem((void **) &channel);
+ ext2fs_free_mem(&channel->name);
+ ext2fs_free_mem(&channel);
return retval;
}
EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
if (channel->block_size != blksize) {
+#ifndef NO_IO_CACHE
if ((retval = flush_cached_blocks(channel, data, 0)))
return retval;
-
+#endif
+
channel->block_size = blksize;
- free_cache(channel, data);
+ free_cache(data);
if ((retval = alloc_cache(channel, data)))
return retval;
}
}
-static errcode_t unix_read_blk(io_channel channel, unsigned long block,
+static errcode_t unix_read_blk64(io_channel channel, unsigned long long block,
int count, void *buf)
{
struct unix_private_data *data;
- struct unix_cache *cache;
+ struct unix_cache *cache, *reuse[READ_DIRECT_SIZE];
errcode_t retval;
char *cp;
int i, j;
data = (struct unix_private_data *) channel->private_data;
EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
+#ifdef NO_IO_CACHE
+ return raw_read_blk(channel, data, block, count, buf);
+#else
/*
- * If we're doing an odd-sized read, flush out the cache and
- * then do a direct read.
+ * If we're doing an odd-sized read or a very large read,
+ * flush out the cache and then do a direct read.
*/
- if (count < 0) {
+ if (count < 0 || count > WRITE_DIRECT_SIZE) {
if ((retval = flush_cached_blocks(channel, data, 0)))
return retval;
return raw_read_blk(channel, data, block, count, buf);
cp = buf;
while (count > 0) {
/* If it's in the cache, use it! */
- if ((cache = find_cached_block(channel, data, block, 0))) {
+ if ((cache = find_cached_block(data, block, &reuse[0]))) {
#ifdef DEBUG
- printf("Using cached block %d\n", block);
+ printf("Using cached block %lu\n", block);
#endif
memcpy(cp, cache->buf, channel->block_size);
count--;
* single read request
*/
for (i=1; i < count; i++)
- if (find_cached_block(channel, data, block+i, 0))
+ if (find_cached_block(data, block+i, &reuse[i]))
break;
#ifdef DEBUG
- printf("Reading %d blocks starting at %d\n", i, block);
+ printf("Reading %d blocks starting at %lu\n", i, block);
#endif
if ((retval = raw_read_blk(channel, data, block, i, cp)))
return retval;
-
+
/* Save the results in the cache */
for (j=0; j < i; j++) {
count--;
- cache = find_cached_block(channel, data, block++, 1);
- if (cache)
- memcpy(cache->buf, cp, channel->block_size);
+ cache = reuse[j];
+ reuse_cache(channel, data, cache, block++);
+ memcpy(cache->buf, cp, channel->block_size);
cp += channel->block_size;
}
}
return 0;
+#endif /* NO_IO_CACHE */
}
-static errcode_t unix_write_blk(io_channel channel, unsigned long block,
+static errcode_t unix_read_blk(io_channel channel, unsigned long block,
+ int count, void *buf)
+{
+ return unix_read_blk64(channel, block, count, buf);
+}
+
+static errcode_t unix_write_blk64(io_channel channel, unsigned long long block,
int count, const void *buf)
{
struct unix_private_data *data;
- struct unix_cache *cache;
- errcode_t retval = 0, retval2;
+ struct unix_cache *cache, *reuse;
+ errcode_t retval = 0;
const char *cp;
int writethrough;
data = (struct unix_private_data *) channel->private_data;
EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
+#ifdef NO_IO_CACHE
+ return raw_write_blk(channel, data, block, count, buf);
+#else
/*
* If we're doing an odd-sized write or a very large write,
* flush out the cache completely and then do a direct write.
*/
- if (count < 0 || count > WRITE_VIA_CACHE_SIZE) {
+ if (count < 0 || count > WRITE_DIRECT_SIZE) {
if ((retval = flush_cached_blocks(channel, data, 1)))
return retval;
return raw_write_blk(channel, data, block, count, buf);
writethrough = channel->flags & CHANNEL_FLAGS_WRITETHROUGH;
if (writethrough)
retval = raw_write_blk(channel, data, block, count, buf);
-
+
cp = buf;
while (count > 0) {
- cache = find_cached_block(channel, data, block, 1);
+ cache = find_cached_block(data, block, &reuse);
if (!cache) {
- /*
- * Oh shit, we couldn't get cache descriptor.
- * Force the write directly.
- */
- if ((retval2 = raw_write_blk(channel, data, block,
- 1, cp)))
- retval = retval2;
- } else {
- memcpy(cache->buf, cp, channel->block_size);
- cache->dirty = !writethrough;
+ cache = reuse;
+ reuse_cache(channel, data, cache, block);
}
+ memcpy(cache->buf, cp, channel->block_size);
+ cache->dirty = !writethrough;
count--;
block++;
cp += channel->block_size;
}
return retval;
+#endif /* NO_IO_CACHE */
+}
+
+static errcode_t unix_write_blk(io_channel channel, unsigned long block,
+ int count, const void *buf)
+{
+ return unix_write_blk64(channel, block, count, buf);
}
static errcode_t unix_write_byte(io_channel channel, unsigned long offset,
{
struct unix_private_data *data;
errcode_t retval = 0;
- size_t actual;
+ ssize_t actual;
EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
data = (struct unix_private_data *) channel->private_data;
EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
+#ifndef NO_IO_CACHE
/*
* Flush out the cache completely
*/
if ((retval = flush_cached_blocks(channel, data, 1)))
return retval;
+#endif
- if (lseek(data->dev, offset, SEEK_SET) < 0)
+ if (lseek(data->dev, offset + data->offset, SEEK_SET) < 0)
return errno;
-
+
actual = write(data->dev, buf, size);
if (actual != size)
return EXT2_ET_SHORT_WRITE;
}
/*
- * Flush data buffers to disk.
+ * Flush data buffers to disk.
*/
static errcode_t unix_flush(io_channel channel)
{
struct unix_private_data *data;
errcode_t retval = 0;
-
+
EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
data = (struct unix_private_data *) channel->private_data;
EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
+#ifndef NO_IO_CACHE
retval = flush_cached_blocks(channel, data, 0);
+#endif
fsync(data->dev);
return retval;
}
+static errcode_t unix_set_option(io_channel channel, const char *option,
+ const char *arg)
+{
+ struct unix_private_data *data;
+ unsigned long long tmp;
+ char *end;
+
+ EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
+ data = (struct unix_private_data *) channel->private_data;
+ EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
+
+ if (!strcmp(option, "offset")) {
+ if (!arg)
+ return EXT2_ET_INVALID_ARGUMENT;
+
+ tmp = strtoull(arg, &end, 0);
+ if (*end)
+ return EXT2_ET_INVALID_ARGUMENT;
+ data->offset = tmp;
+ if (data->offset < 0)
+ return EXT2_ET_INVALID_ARGUMENT;
+ return 0;
+ }
+ return EXT2_ET_INVALID_ARGUMENT;
+}
git://git.whamcloud.com / tools / e2fsprogs.git / blobdiff